Fix RO JMX register/Unregister

1) Stores JMX are registered by JmxService class.
2) Previously ReadOnlyStorageConfiguration registered the same metrics
by prepending the NodeId. As Part of the commit

2aec46a#diff-005b79e324515c9e1045a61d0aee6d07

I fixed it and removed the NodeId. But I did not realize that this
caused the name collission and overwriting.

[18:50:45,445 voldemort.server.jmx.JmxService] WARN Overwriting mbean
voldemort.store.readonly:type=test2 [main]
[18:50:45,447 voldemort.server.jmx.JmxService] WARN Overwriting mbean
voldemort.store.readonly:type=test1 [main]

Now ReadOnlyStorageConfiguration does not register any JMX Metric at
all. Used the JConsole to verify that it is the same object registered
under two different names. Now the duplicate one is gone and the
warnings on the shutdown of Read Only server will be gone as well.

src/java/voldemort/store/readonly/ReadOnlyStorageConfiguration.java

@@ -17,13 +17,6 @@
 package voldemort.store.readonly;
 
 import java.io.File;
-import java.lang.management.ManagementFactory;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Set;
-
-import javax.management.MBeanServer;
-import javax.management.ObjectName;
 
 import voldemort.VoldemortException;
 import voldemort.routing.RoutingStrategy;
@@ -32,7 +25,6 @@
 import voldemort.store.StorageEngine;
 import voldemort.store.StoreDefinition;
 import voldemort.utils.ByteArray;
-import voldemort.utils.JmxUtils;
 import voldemort.utils.ReflectUtils;
 
 public class ReadOnlyStorageConfiguration implements StorageConfiguration {
@@ -41,7 +33,6 @@ public class ReadOnlyStorageConfiguration implements StorageConfiguration {
 
     private final int numBackups;
     private final File storageDir;
-    private final Set<ObjectName> registeredBeans;
     private final SearchStrategy searcher;
     private final int nodeId;
     private RoutingStrategy routingStrategy = null;
@@ -52,7 +43,6 @@ public class ReadOnlyStorageConfiguration implements StorageConfiguration {
     public ReadOnlyStorageConfiguration(VoldemortConfig config) {
         this.storageDir = new File(config.getReadOnlyDataStorageDirectory());
         this.numBackups = config.getNumReadOnlyVersions();
-        this.registeredBeans = Collections.synchronizedSet(new HashSet<ObjectName>());
         this.searcher = (SearchStrategy) ReflectUtils.callConstructor(ReflectUtils.loadClass(config.getReadOnlySearchStrategy()
                                                                                                    .trim()));
         this.nodeId = config.getNodeId();
@@ -62,9 +52,7 @@ public ReadOnlyStorageConfiguration(VoldemortConfig config) {
     }
 
     public void close() {
-        MBeanServer server = ManagementFactory.getPlatformMBeanServer();
-        for(ObjectName name: registeredBeans)
-            JmxUtils.unregisterMbean(server, name);
+
     }
 
     public void setRoutingStrategy(RoutingStrategy routingStrategy) {
@@ -83,13 +71,6 @@ public StorageEngine<ByteArray, byte[], byte[]> getStore(StoreDefinition storeDe
                                                                 numBackups,
                                                                 deleteBackupMs,
                                                                 maxValueBufferAllocationSize);
-        ObjectName objName = JmxUtils.createObjectName(JmxUtils.getPackageName(store.getClass()),
-                                                       storeDef.getName() );
-        JmxUtils.registerMbean(ManagementFactory.getPlatformMBeanServer(),
-                               JmxUtils.createModelMBean(store),
-                               objName);
-        registeredBeans.add(objName);
-
         return store;
     }
 
@@ -107,12 +88,5 @@ public void update(StoreDefinition storeDef) {
      */
     @Override
     public void removeStorageEngine(StorageEngine<ByteArray, byte[], byte[]> engine) {
-        ReadOnlyStorageEngine store = (ReadOnlyStorageEngine) engine;
-
-        if(this.voldConfig.isJmxEnabled()) {
-            ObjectName objName = JmxUtils.createObjectName(JmxUtils.getPackageName(store.getClass()),
-                                                           store.getName() + nodeId);
-            JmxUtils.unregisterMbean(ManagementFactory.getPlatformMBeanServer(), objName);
-        }
     }
 }